COULD NEANDERTHALS SWIM AND DIVE?

Over 100,000 years ago at the Grotta dei Cavalli (Cave of Horses) on what is now the northwestern tip of Sicily, a group of Neanderthals made tools from clamshells - one of only three sites in the world where strong evidence has been found of systematic shell scraper manufacture by Neanderthals, another being the Grotta dei Moscerini (Cave of Gnats), a large seaside cave at the base of a cliff on the tip of Italy's boot-heel about 500 kilometres to the northeast.

The tools were found throughout multiple archaeological layers dating from 106,000 to 74,000 years ago, but were not distributed evenly throughout the Neanderthal-associated sequence; where shell tools were common, stone tools were not.

Neanderthals made stone tools, but their shell-based toolmaking is less well-known. In 1949, archaeologists found 171 at Moscerini. Another 136 were separately found at Cavalli, and much smaller numbers in other Neanderthal sites such as Kalamakia Cave in Greece.

The assumption had been that the Neanderthals picked up shells on the beach, but between a fifth and a quarter of the specimens found at the two sites in Italy seem to have been collected alive. All were made from the smooth clam, Callista chione. The shells are almost evenly thin from the bulge of the half-shell to its edge. Edges were shaped with stone hammers, and experiments demonstrate that unlike stone the cutting edges of the shells can be retouched two to three times without changing the cutting angle.

Studies show that Neanderthals preferred meat but also caught fish in shallow freshwater and ate shellfish. Neanderthals 115,000 years ago in what is now Spain bored holes into shells and colored and decorated them. Erik Trinkaus of Washington University in St Louis, USA, reports evidence of "surfer's ear" in Neanderthal skulls - bony growths in the ear canal prevalent among humans who swim in cold water.